Andrew Garfield wanted to startle Silence audiences with emaciated appearance

Actor Andrew Garfield shed 40 pounds (18 kilograms) for his new movie Silence because he wanted to stun viewers with his emaciated frame.

The Amazing Spider-Man star portrays a 17th century Jesuit priest attempting to find Christian converts in Japan in Martin Scorsese's new drama, and Andrew was determined to appear as thin as possible onscreen.

"It's not fun," he told E! News of slimming down. "But ultimately (it's) very, very satisfying and fulfilling. You learn a lot of information from emptying out."

He wanted to stir a reaction from audiences when they first set sight on his skin and bones appearance to really hammer home the struggles his character faced.

"I think it has to be (startling)," the British actor explained. "It's the truth of what these guys would have gone through."

Garfield's co-star Adam Driver also drastically starved himself for the film, and they both endured a stint at a silent Jesuit retreat in Wales to prepare for the shoot. Luckily the 33-year-old is a big fan of "spiritual exploration" and was fascinated by his time at the facility.

"It's a wonderful thing," Garfield shared. "Just after about three days everything shifts. Your central nervous system just kind of settles down and it becomes normal.

"You go into all these meditation and prayer rooms and the quiet in there is the loudest thing you've ever f**king heard. It's crazy. You literally go in there and your ears start ringing. it's the purest silence that you could know. I've done a few of these things in the past on my personal time."

Silence, also starring Liam Neeson, hits cinemas in January (17) and is already receiving rave reviews from critics.